Reinforced sheet-glass and method of making same.



C. 6I V. SHUMAN.

REINFORCED SHEET GLASS AND METHOD 0F MAKING SAME.

APPLICATION FILED NOV. 22. I9I6.

- N #SEH UNITED sTATEs PATENT oEEIoE..

CONSTAN TINE SHUMAN AND VICTOR SHUMAN, 0F PHILADELPHIA, PENNSYLVANIA.

BEINFORCED SHEET-GLASS AND METHOD OF MAKNG SAME.

Original application led April 20, 1916,

To all whom t may concern.'

Be it known that we, CoNsTANTINE SHU- MAN and VICTOR SHUMAN, citizens ofthe United States, and residents of Philadelphia, county ofPhiladelphia., and State of Pennsylvania, have invented an Improvement,in Reinforced Sheet-Glass and Methods of Making Same, of which thefollowing is a specification.

The object of our invention is to provide an improved method for makinga compound transparent. or translucent composite sheet composed of twosheets of glass with an interposed sheet of yCelluloid welded to theglass sheets and uniting them to the celluloid to form a. unitarystructure.

Heretofore, the makingv of a transparent composite sheet, :by pasting asheet of Vcelluloid or equivalent material between two sheets of glassby some kind of cement, or by softening and dissolving the surfaceportions of the celluloid sheet with a solvent of celluloid and withsuc-h prepared celluloid sheet pasting the two glass sheets togetherwhile under pressure, has been known; these processes have, however,serious object-ions and the products produced by their use have y not`been .found satisfactory. .In case a cement is used, it has been foundthat the proper results cannot be obtained without adding a materialwhich has tendency to discolor in time; and in case a solvent is used todissolve the outer surfaces of the celluloid to form aI celluloidcement; it has been found impossible to remove all of the sol- `vent,that remalning imparting a weakening of the products.

In order to secure a desirable transparent compound sheet which shallpossess the propcrty of not allowing glass splinters, or pieces to fallo'fl' when struck and cracked by a hard blew, we have found ,itnecessary that the compound sheet shallbe composed solely of glass andcelluloid, the latter in its normal state and not weakened by theaddition of any solvent.

Our improved process of making. composite, transparent or translucentsheets,

consists of assembling a sheet of 'Celluloid between two sheets of glasspreviously prepared with dry celluloid coatings, the said glass sheetsbelng respectively arranged one on each side of the s heet of Celluloid,and subjecting the assembled sheets to welding Specification of LettersPatent. Patented July 30, 1918.

Serial No. 92,355. Divided and this application filed November 22, 1916.Serial No. 132,732.

pressure, and at or before the application of the said pressure, raisingthe temperature, preferably to approximately 230 degrees Fahr., nextapplying a higher pressure, and after maintaining the assembled productunder this heat and pressure for a' predeter-` .feature of ourinvention, we prefer that the vacuum shall not only be maintained in thespa-ce occupied bythe sheets, Ibutalso with-- 1n the space containingthe pressure applying fluid, whereby the vacuum is essentially forextracting the air from between the lass and celluloid and not forthepurpose o applying the operative pressure to insure the welding of thesheets together.

Our invention contemplates the use of a. sheet containing compartment,Dfrom which, prefer-ably, the air'may be exhausted, and aninclosinpressure chamber in which a pressure may e created, the wall orwalls between the compartment and the "inclosing chamber being flexiblewhereby the pressure of the inclosing chamber may be applied to thesheets of glass and Celluloid to prs them togther Ito form the weldedunion, as afore-v sa1 Y Our invention also comprehends certain otherfeaturesof invention, which, together with those above specified, willbe better un-l derstood -by the more detailed description hereinaftercontained and by the definitions thereof reci-ted in the claims. 4

Our improved apparatus in which tov cal out our special process ormethod is fully illustrated in the drawings, in which Figure 1 is anYelevation of our improved apparatus with the compartment and 'cham-I berin section;`Fig. 2 is a plan viewof 4the same with part in section; Fig.3 is an enlarged sectional view of a portion of Fig. l1;. and Fig. 4 isa cross sectlon 021e sheet of glass coated with the layer of ce uloidpre; lminary to the welding operationy v2 is a met-al pot and isprovided with a` removable cover 3 which is ,detachabl clamped to thepot by bolts 3. The widt and length of this pot are required to be largeenough to take in the frame 36 in which the glass to be treated isplaced, but the' height of the pot may be relatively small. Thereforethe dimensions of the pot shown are in no way to be taken aslimitations.Water or fluid is delivered into the pot through a pipe 5 and is forcedtherein by a force pump 6, whereby desired pressure may be provided. Thepipe' preferably enters the pot at or near its bottom and a circulatingpipe 13 opens from the pot at a materially higher level and communicateswith a coil 14 in a tank 15, the other end of t-he coil being connectedwith the pipe 5 at a pointbetween the pump 6 and the pot. At a suitableplace between the coil 14 and the pot and in the pipe 5 is arranged acirculating pump 8 of any suitable character, the

purpose of which is to draw the fluid through the coil 14 and force itinto the pot and permit it, after circulation therethrouglf, to pass bythe pipe 13 into the other end of the coil. Thetpipe 13 is provided witha pressure gage 24 and with a temperature gage 25, so that the pressurewithin the pot and the temperature of the circulating fluid therein maybe readily known at any time during theprocess. The pipe 5 between thecirculating pump 8 and the pressure pump 6 is provided with a shutoffvalve 7 which is preferably closed when the circulating pump is inoperation. Vhile this valve 7 is not essential in view of the checkvalves employed in the force pump 6, nevertheless it is desirable toprovide a positive valve 7 which may be closed during the vcirculationof the fluid when under high pressure, that the said pressure may bepositively maintained. The tank 15 is provided at the top with a steampipe 16 having a valve 17 and a water overflow pipe 22 having a valve23. The bottom o f this tank is pro,- vided with a drain pipe 18 havinga valve 19, and a water inlet pipe 20V having a valve 21. If the valves21 and 23 are closed and valves 17 and 19 are opened, steam may passinto the tank around the coils 14 to heat the fluid,`and the water ofcondensation will flow ofl1 byl the pipe 18. If high pressure steam isemployed, the valve 19 maybe opened only just sufficient to let thewater of condensation drainoff under the initial pressure of the steamwithoutpermitting an excessive escape of steam. `Furthermore, the airliberated by lthe condensation of the steam is passed over with thewater of condensation so that the tank does not become air-bound. Inthis manner, lthe circulating fiuidthrough the pot 2 may be heated tothe desired degree.. If, on the other hand, valves 17 and 19 are closedand the valves 21 and 23 aie opened, then the cold Water will enter atthe bottom of the tank and fill it and flow out of the pipe 22. In thismanner, the

circulating fluid through the coils 14 will be cooled. By the apparatusjust described, it will be evident that the temperature of thecirculating fluid in the pot 2 may be either heated or cooled to anydesired degree, and the time under which these actions are maintainedmay be predetermined to suit 'the requirements of the process.Duringthese operations, the temperature conditions may be readily readby the gage 25.

In filling'the pot, it is manifest that the same might be filled throughthe pump 6 and pipe 5, but as this would be slowand not as satisfactoryas filling the pot by the normal hydrant pressure of the street mains,we prefer to connect with the pipe 13 a water feed pipe 26 having avalve 27. Furthermore, the cover 3 of the pot is provided with anoverflow pipe 11 having a shutfoff valve 12. This overfidt@ pipe 11 ispreferably located at the highest interior part of the pot chamber, sothat air may readily flow out of the pot in the act of filling it, butthis is not essential if a vacuum pump is employed as provided forhereinafter. In filling the pot after the cover has been clamped tightlyin position, the valves 27 and 12 are opened and the water or fluidpasses through pipe 26 and pipe 13 into the ypot, while the air flowsout of the pipe 11 from the upper partof the pot. When the watercompletely fills the pot and begins to iiow out of the pipe 11, it willbe known that lthe pot is completely full and then the valves 27 and 12are closed. In the filling of the pot in this manner, there would be noappreciable pi'essure within the pot, and it will therefore beunderstood that whatever pressure is required will be provided by theoperation of the .pressure pump 6 which introduces the additional waterthat may be required to bring th'e pressure to' the desired degree, ashereinafter described..

JV When it is ldesired to drain'the pot 2, the

painting or spraying'with'a very thin layer p of celluloid dissolved ina solvent which', for example, may be a mixture of 95% alcohol and 5%crystallized camphor placed upon opposite sides f a'sheetof cc1 luloidwith their painted or coated-surfaces in contact therewith. A coatinkind sticks very tightly to the g ass; and afterall of the solvent hasbeen evaporated (which may be assisted by hightemperaturc orotherwise),'the remaining deposit is pure Celluloid as a thin skin onthe glass and very tightly adherentthereto. As Celluloid will weldsomewhat better to celluloid than it and when dry of this will to glass,this pre-treatment of the glass to obtain a very thin skin of pureadhering celluloid is an advantage to the process and the product.

This reference to the coating of the glass with celluloid in a solventis not to be confused withv the idea of sticking the glass sheetstogether by said coatings as a cement and subsequently evaporating thesolvent, as the solvent in this case is a mere incident to coating thesurface of the glass withv a very thin layer of pure tightly adheringcelluloid which is in a dry hard condition upon each sheet of the glassbefore they are assembled in connection with the celluloid sheet withinthe apparatus and to 'receive treatment by the special process hereinset out. Theresult is a true welding together of a surface of adherentlycoateddry celluloid to another surface of celluloid under heat andpressure. We will now describe the means of supporting Xthe layers ofcoated glass and celluloid in proper relation to insure their beingwelded together, while being subjected to the-action of temperature andpressure provided by the fluid contents of the pot. A frame 36 toprovide a hollowv chamber 44 is arranged to be supportcdupon the lateralprojections or lugs 4 from the -side walls of the pot at a distanceabove the bottom thereof. This frame 36 comprises a lowerrectangularheavy frame 37 and a similar upper rect-angular heavy frame38, between which is clamped a corresponding frame 39 which acts as aspacing frame to insure the proper vertical width of space 44 in whichto locate the coated glass and celluloid. On veach side of theframe 39is a rectangular packing 'or gasket 4l, and arranged between thesegaskets and the respective frames 37 and 38 are flexible sheets 42and-43 of galvanized iron or other suitable metal, or if desired, thelower sheet 42 might be of galvanized iron and the upper sheet 43 ofcopper to give somewhat more exibility. The several frames 37 38 and 39are bolted together by the numerous bolts 4Q, and in that manner theframe parts are clamped .together toma-ke a Huid-tight chamber 44between the metal plates 42 and 43. 45 and 46 represent the two sheetsof coated glass, and 47 lis a sheet of celluloid arranged between theglass sheets, and`theSe three sheets are placed within the chamber 44resting upon the lower met-al sheet 42- and having` the upper sheet 43close to the surfaceiof the upper sheet of glass. It-will be understoodthat when the pressure is appliedto the fluid in the pot surrounding theframe 36, the iexible sheets 42 and 43 will be forced toward each otherand press uniformly over the lower operating surfaces of therespective'glass sheets and force them tightly. upon each side; ofthecelluloid, 00mpressing the latter between them and into tightintimate contact. If air Was within the chamber 44, said air would becompressed during the pressing of the sheets together, and the air,etween the glass and the celluloid would be forced out during thewelding operation. We, however, prefer to provide exhausting means bywhich the air may be exhausted from the chamber 44 after the 'glass andcelluloid .have been sealed therein. .To permit the exhaustion of theair, the intermediate annular frame 39 is. provided with a vent 48terminating in a tube 49. If it is desired to exhaust the air from thechamber 44 before it is put into the pot, that may readily be done bywithdrawing the air through sealing it. lVe prefer, however, t0 exhaustthe air from the chamber 44 after the frame 36 has been placed in thepot 2 and during the operation o`f the process.l The' means employed forthis purpose and for exhausting the air from the pot 2 itself are asfollows:-A vacuum pump 32 is connected by pipes 28 and 31 with the pot2, and said pipes 28 and 31 extend upward above the top 'of the pot andpreferably connect through a reservoir chamberc30. .A valve 29 may beprovided in the pipe 28` adjacent to the pot to close the communicationwith the :vacuum devices after the exhaustion has beenlcomplete andbefore 'the pressure is applied by the pump 6. Branching from the pipe31 is a pipe 33 having a valve 34,- said pipe opening into a passagethrough the pot wall, the inner end of which is provided with a. nipple35 in' alincment with the pipe 49, and these two .are connected by aheavy rubber union 50 during the operation of the process. By openingthe valve 34, the chamber 44 in the frame 36v may be exhausted ofall-air, and any desirable extent of'vacuum may be provided and the pipe49 and maintained, if desired, within the said chamber 44 during theoperation of the process.

Whatever vacuum is produced in thechamber 44 (in which the glass andcelluloid arev located may also bey produced in the pot in which theframe is located. when exhausting the air from the chamber 44 andprevious to the applying of the pressure in the pot, so that iio thegeneral pressure conditions inside and outside .of the chamberI 44hausting of the air from between them, and

consequently guards against interference with free withdrawal ofthe airwhich might otherwise be entrained. After this action is accomplished,the valve 29, and if desired, the valve 34, will be Closed, and then thepressure would be appliedin the pot 2 by the pressure pump 6 tointroduce the posi! .12 for a moment, and then Closing it or by pumpingin the water.

While ordinarily, water may be used as the pressure fluid in the pot 2,it is to be understood that we do not restrict ourselves to a liquid, asair or any suitable gas may be employed as the iiuid for Controlling thepressure and supplying the temperature to the chamber 44 in which theglass and Celluloid are located, and therefore in using the word fluidwe are using it in a generic sense.

lVhile the use of a vacuum in the Chamber 44, either with or without'avacuum in the pot as a preliminary operation, is desirable, because itremoyes any possibility of small bubbles of air remaining between theassembled sheets of glass and Celluloid, nevertheless we do not restrictourselves in this respect, for as before pointed out, the generalprocess may be operated without the use of a vacuum. The specialadvantage of employing a vacuum in the pot outside of the chamber 44 atthe same time that a vacuum is being applied within the chamber 44,resides in the fact that by removing the atmospheric pressure whichwould be applied to the sheets 42 and 43 (under the Conditions of aVacuum in the chamber 44 alone), there is no compression put upon thesheets of glass and Celluloid during this exhausting operation, andconsequently the atmosphere of the chamber 44 can be rareied to thehighest degree possible, and then while there is no air present inchamber 44, the pressure may be applied in the pot 2 by means of theiiuid and pump 6 to insure the compression of the glass sheets upon theCelluloid to provide a perfect welding of the surfaces without anypossible entraining of air, even in rarelied Condition, between the'surfaces of the glass and Celluloid.

It will also be seen that by this process of confining the sheet withinthe inclosed chamber 44 `of frame 36, not only are the Coated glass andCelluloid in Contacting relation in a vacuum, but the union between thecoated glass and Celluloid at the edges thereof is thoroughly protectedby the. in- Closing chamber 44 during the time that the pressure isapplied within the pot and put upon the surface 'of the glass from theoutsidevof the frame 36, thereby insuring a veryv thorough welding andwith the Celluloid in a perfectly solid and dry condition,'sQ that whenthe composite glass sheet is subsequently released from its confinementwithin the frame 36, there is no possibility of the atmospheric pressureentering between the glass and Celluloid to interfere in any manner withthe perfect welded union Ywhich has been made.

Briefly stated, the process of operation for welding together the twosheets of coated glass 45 and 46 to an intermediate sheet of Celluloid47, is as follows z-The sheets of Coated glass, preferably with theircontacting surfaces perfectly clean` are placed upon opposite sides of aclean sheet of Celluloid 47, and these sheets are then placed within theframe 36 after the top plate 43 andv frame 38 have been removed. Theseparts are then placed in position and the bolts 40 inserted andtightened so as to make the chamber 44 air-tight except so far asCommunication may be had through the nozzle or'tube 49. rThis frame 36thus charged with the glass and Celluloid is then placed in the pot andrests upon the lugs 4 and preferably with the greatest clearance betweenat the end most distant from where the water is circulated throughpipeThen the frame 36 is placed in position in the pot, the pipe 49 isCoupled to the'nipple 35 by the rubber union 50.

The valve 10 being closed and the Cover 3 being tightly clamped inplace, water is admitted by the pipes 26 and 13 into the pot. The airwithin the pot is allowedto escape through the vent 1.1., the vaive l2of which has been opened. The water kfills the pot as well as the pipes13, 5 and coil 14, and will also lill the circulating pump 8, andif thevalve 7 is opened, the water may extend all the way back to the pressurepump 6. When the water begins to flow from the overflow pipe 11, thevalve 12 is Closed, the valve 27 is also closed, and the vacuum pump 32put into operation with the valves 29 and 34 opened. When the desireddegree of vacuum has been put upon the chamber 44 and also upon thewater in the pot 2, the valve 29 is Closed and the valve 34 may also beclosed, or, if desired, valve 34 may be left open and the vacuum pumpcontinue to act in maintaining the vacuum Within the Chamber 44. Anysuitable well known means may be employed to indicate the extent ofvacuum. After the removal are started into circulation by thecirculating pump 8. r,I his Circulation enters the pot by pipe 5pass1ngunder the frame 36 to the dis tant side, thence upward around the end ofthe frame and back over the frame and 90 the end of the frame and theside of the pot y thence out by the pipe 13. To insure this circulationto the extremeend of the frame 36, a loose baille plate 3Ga may beallowed to rest upon the top of the frame 3G closing the 5 space betweenthe pot and frame at its sides and end nearest to the pipes 5 and 13, asindicated at 3Ga in Fig. 1, and in dotted lines in Fig. 2. The fluidfrom the pipe 13 passes through the coil 14 and back to the pump 8.

During this Circulation steam is turned on to the tank 15 by valve 17,and in passing over thecoil 14 gives up itsl latent heat to theCirculating water within the coil and the condensed water passes to thebottoni and 15 out by pipe 18 and valve 19. The temperature of the'Circulating fluid is gradually raised until the fluid is heated to about230 degrees Fahr., and at this temperature the fluid is Conducted to theglass and Celluloid and softens the latter, while held under the gentlepressure of ten pounds per square inch'. The temperature of thecirculating fluid may be observed by the thermometer and in this mannerregulated as may be 25 required. After the temperature has reached about230 degrees Fahr., and while the fluidv is still being circulated by therotary pump 8, a small additional amount of fluid is pumped into thesystem by the pump 6, the valve 7 being temporarily opened for theadmission of this additional fluid. This addition of the circulatingfluid is made very gradually and until the pressure gage 24 indicates apressure of about one hundred pounds (by way of example). This increasedpressure is therefore applied to the Celluloid betweenthe two glasssheets and at a time that the Celluloid is softened by the temperatureof the circulating fluid. After a reasonable length of time to insurefull setting of the glass and Celluloid into thorough and intimatecontact (which may be from five to thirty minutes, according to thethickness of the glass), the steam is shut olf by valve 17 and valve 19is also closed. Cold water is then admitted. by valve 21 and allowed tooverflow by opening the valve 23; This cold water flows over thecoils'14 and Cools the circulatingfluid, the latter' still beingcirculated by the rotary pu mp 8. In this manner, the Circulating fluidis Cooled until the thermometer indicates about 100 degrees Fahr., whichis sufficiently low for handling and removing the glass. v After thecirculating fluid and the glass within the frame 36 have thus beencooled, the pressure is gradually released by opening the overfiow valve12 until atmospheric pressure is within the pot2. The drain valve 10 isthen opened-and the Huid contents run off from the pot 2 by the drainpipe 9, or at least sufficiently loW to expose the frame 36 containing'the u glass and Celluloid. The Cover 3 of the pot 2 is then removed.The

vacuum valve 34 isthen closed; The frame 36 is then lifted out, havingbeen disconnected from the rubber tube 50. The vacuum is thus brokenwithin the Chamber 44. The frame 36 may then be opened by removing thenuts from the bolts LLO-and lifting olf the upper frame`38 and itsflexible metal sheet 43. The composite glass and Celluloid sheet is thenremoved.

While we have designated certain temperatures and pressures by way ofeXample,' we -75 do not restrict ourselves tothe same as anytemperatures and pressures suitable may be employed, but those statedhave been found satisfactory in commercial practice. In some Cases, theWelding pressure may be raised very high even to one thousandl pounds ormore per square inch wheie very thick plates of glass are to be Weldedto the Celluloid.

While We have described the preferred method. of producing -the desiredAsheets of Composite material, especially Where sheets of thin glass andlarge area are to be united to the celluloid, neverthelessfor smallsheets and especially where the glass is thick, the particular steps ofthe process may be va ried'. For instance, if the composite sheet is tobe ofmedium'area and be formed of thick glass, the entire pressure maybe promptly applied even before the heating of the Coated glass andCelluloid takes place, or the heating and the pressure may be applied atthe same time. It will be understood of course that to insure a properWeld between the Celluloid and the coated glass, it is essential thatthe Celluloid shall be heated so as to be softened and Conform t'o thegeneral surface of the glass at the time that the pressure is beingapplied, but its immediate time of application may be before or duringlthe application of such welding pressure, In the Case of thin sheetswhere the glass mightv readily crack, it is preferable to first applythe temperature to soften the celluloid before (applying the Weldingpressure. It is also to be understood that while it is preferable (wherethin sheets of glass are employed) that there shall be. a preliminarylow pressure applied to the coated glass and Celluloid sheets before thecelluloid is softened, and before the application of a-full pressure.this preliminary low pressure may be omitted where desired, andespecially where the glass sheets are relatively thick. 130

It will be observed that in formin a composite sheet of cellulo'd withouter glass faces in the manner herein described, the two coated glasssheets are held together by the Celluloid sheet which is Welded to 125'each of the glass sheets and acts as a binder between them, and thisWelding operation is by thorough intimate Contact between the glass aridCelluloid with the complete exclusion of air, and consequently amost'prac- 130 tical and strong structure is secured. It will further benoted that when the Welding is donel in this perfect manner, thetransparency of the comp'osite glass and celluloid sheet is mostexcellent; and as celluloid alone isi/used between the two glass sheets,the tendency to discoloration is i eliminated.

It will now be apparentth'at We have devised a novel and useful methodand means for carrying the same into practice and produce thereby animproved product as an article of manufacture, which embody the featuresof advantage enumerated herein as delsirable, and While we have in thepresent instance shown and described by Way of example the preferredembodiments thereof which have been found in practice to givesatisfactory and reliable results, it is to be understood that We do notrestrict ourselves to the details, as the same are susceptible ofmodification in 'various particulars Without departing from the spiritor scope of the invention.

In thisY application no Claim is made to the apparatus nor to the methodin Which Cleanvfaeed sheets of glass are directly Welded to sheets ofcelluloid, nor to the product produced by such method, as the apparatus1s set out inour application Ser. No. 182,733, filed Nov. 2Q, 1916, andthe method and product are set out in our application Ser. No. 92,355,filed April'QO, 1916, of Which this application is a division.

Having now described ourinvention, what We claim as 'new and desire tosecure by Letters Patent, is

1. As a new article of manufacture, a comfpo'site sheetthrough whichlight may pass `to a greater or less, extent, consisting of two sheetsof glass united by a compound sheet composed yof a relatively thicksheet of pure elluloid and two relatively thin layers of Celluloidrespectively Welded Vupon the opposite surfaces of the pure Celluloidsheet to the `exclusion of all 'air and said relatively l thin layers ofCelluloid having their other surfaces thoroughly welded'to therespective opposing surfaces of the tWo sheets of glass and to theentire exclusion of air.

2. 'lhe herein described method of producing composite sheets throughwhich light rays may pass to a greater or less extent, which consists inassembling two sheetsof glass each `having a thin coating of tightlyadheringcelluloid, upon an interposed separate sheet of Celluloid, saidCelluloid in direct contact with the Celluloid coatings of the glasssheets, and welding the Celluloid sheet to the Celluloid coated glasssheets by the application of heat and pressure.

3. The herein described method of producing Composite sheets throughwhich light rays may pass to a greater or less extent,

which consists in assembling two sheets of glass each having a thincoating of tightly adhering celluloid, upon an interposed separate sheetof celluloid, Vsaid Celluloid in direct Contact with the Celluloidcoatings of the glass sheets, and Welding the Celluloid sheet to theCelluloid Coated glass sheets by the application of heat and pressure,and during the said Vapplication of pressure maintaining the edges ofall of the sheets under the inHuence of a vacuum.

11. The herein described method of producing Composite sheets throughwhich light rays may passte a Ygreater or less extent,

Which Consists in first coating tWo glass sheets with a thin layer ofpure Celluloid and after the said Celluloid coating is in dry condition,assembling said glass sheets With their coated surfaces upon oppositesides of a sheet of Celluloid, and Welding the Celluloid coatings andCelluloid sheet together by the application'of heatand pressure, andduring said operation maintaining the edges of all of the sheets underthe iniuence of a vacuum.

ln testimony of Which invention, we hereunto set our hands.

CONSTANTIN'E SHUMAN VCTOR SHUMAN. vWitnesses:

CHAs. W. DUNKER, ADELAIDE B. WATSON. t

